Question: Khan.scratchpad.disable(); Emily sells magazine subscriptions and earns $$7$ for every new subscriber she signs up. Emily also earns a $$20$ weekly bonus regardless of how many magazine subscriptions she sells. If Emily wants to earn at least $$86$ this week, what is the minimum number of subscriptions she needs to sell?
Solution: To solve this, let's set up an expression to show how much money Emily will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Emily wants to make at least $$86$ this week, we can turn this into an inequality. Amount earned this week $\geq $86$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $86$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $7 + $20 \geq $86$ $ x \cdot $7 \geq $86 - $20 $ $ x \cdot $7 \geq $66 $ $x \geq \dfrac{66}{7} \approx 9.43$ Since Emily cannot sell parts of subscriptions, we round $9.43$ up to $10$ Emily must sell at least 10 subscriptions this week.